Automatic firearm



Dem 23, 1941 v. HoLEK 2,267,501

' AUTOMATIQFIREARM Filed July '7, 1939 Fig! 2 5 2l 8 22239 I6 l5.

E {Mm/010% Patented Dec. 23, 1941 AUTOMATIC FIREABM Vclav Holek, Zabovresky, Brunn, Czechoslovakia, assignor to eskoslovensk Zbrojovka a. s., Brno, Brunn, Czechoslovakia, a company of Czechoslovakia Application July 7, 1939, Serial No. 283,260 In Czechoslovakia July 13, 1938 5 Claims.

The present invention relates toran automatic firearm of the kind comprising a breech block the movements of which are controlled by a breech-block carrier. In the case of firearms of this kind, there is a danger that, in the case of a too sudden forward movement of the breechblock carrier, the breech-block will rebound on striking the end wall of the barrel and the firing of the gun will take place with the breech block prematurely unlocked, or that the propelling spring will be fatigued and the forward movement of the breech-block carrier will be gradual, so that premature firing can take place with the breech-block unlocked. These two defects resuit in stoppagea e. g., breaking of the cartridge and, consequently, the rendering of the firearm inoperative for a long time.

The chief object of the present invention is the construction of a firearm which is' safe and wherein the aforesaid defects cannot occur.

According to the present invention, there is arranged between the breech-block carrier and the breech block, a device in which there is stored up, during the recoil movement of the breech-block carrier, energy, which, on the locking movement of the breech block during the forward movement of the carrier, is released in such a manner that it effects an accelerated movement of the carrier, in the direction of the forward movement, in relation to the locked breech block. On account of the provision of such a device between the breech-block carrier and the breech block, not only is the locking movement of the breech block accelerated by reason of the fact that the force of the movement of the breech-block carrier is increased towards the end of the locking movement, but the locking of the breech block is assisted for a greater distance by the forward movement of the carrier than hitherto.

In order that the present invention may be clearly understood and readily carried into effect,

the same will now be described more fully, by way of example, with reference to the accompanying drawing, in which:

Figure 1 is a. longitudinal vertical section of an automatic firearm according to the invention, the said firearm having a tiltable breech-block which is shown locked at the instant of firing,

Figure 2 is a fragmentary longitudinal vertical section, on a larger scale, the breech block being shown in its opening movement,

Figure 3 is a similar view to Figure 2 but showing the breech block at the commencement of the locking movement thereof, and

Figure 4 is a fragmentary longitudinal vertical section showing a. modification.

Referring first more particularly to Figures 1 to 3 of the drawing; I denotes the barrel which is rigidly connected to a casing 2 inside which there moves the breech mechanism which comprises a breech-block carrier 3 and a breech block proper 5 provided with a sprung firing pin 2l. The recoil of the breech-block carrier in conjunction with the breech block is, in the example shown in Figures 1 to v3, derived from the pressure of the propellant gases which pass from the barrel I and through a passage 6 into a. gas tube I in which there moves a piston 4 which is connected with the breech-block carrier 3 by means of a piston rod. The breech-block carrier 3 is, on its upper side, provided with two projections l. and 9 which control the breech block on the locking and unlocking thereof. On the under side of the breech-block carrier 3, there is provided a tooth I0 which co-operates with a trigger Il of trigger mechanism of known construction which is arranged in the casing 2. The breech block 5 is provided, on its sides, with lugs I3 having curved guiding surfaces which rest on pins I4, arranged on the walls of the casing 2, and effect the tilting of the breech block 5. The forward movement of the breech-block carrier 3 is produced by a propelling spring l5 which is fitted on a guide rod IB.

Between the breech block 5 and the carrier 3 there is arranged a device which stores up energy at the commencement of the recoil of the carrier 3 and releases it again in the forward movement on the unlocking of the breech block. In the example shown in Figures 1 to 3, the device consists of two springs I1 which are arranged symmetrically on the two sides of the projection 8 or of the projection 9 and which are fitted on 'guide rods I8 which bear, with their rounded heads I9, against curved surfaces of projections on the breech block 5. Springs I'I bear at one end thereof against the head I9 and at the other end rest on a guiding stirrup 20 provided with eyes or the like through which pass the guide rods I8, the said guide rods having secured thereto limiting pins, cotters or the like adapted to abut against the stirrup 20. In the example shown, for the purpose of ready assemblage, the stirrup 20 is let into the breech-block carrier 3 by means of a dovetail, thus facilitating the action of the springs II on the carrier 3. i

At the instant of firing, the breech device is located in the position shown in Figure A1, in which the breech block, which is supported by the projection 9 of the carrier 3,'bears with a rear bevelled face 22 thereof against a supporting face 23 on the casing 2. As soon as the projectile covers the passage 6 in the barrel, the explosive gases begin to act on the piston 4 so that the said piston begins to move back with the lcarrier 3. The carrier 3 unlocks the breech block 5 owing to the action of the projection 8, the carrier 3 performing a definite movement in relation to the breech block 5 during unlocking. From the beginning of the movement of the carrier 3 up to the complete` unlocking of the brecnbmck 5, that is to say when the faces 22 and 23 are disengaged from each other, not only is the propeiling spring I compressed but the two springs I1 are compressed on account of the displacement of the stirrup 2D, which springs I1 bear against the breech block; energy is thus stored up inthe springs I1. On the completion of the un-locking movement, the edge 24 of the breech block 5 bears against a vertical wall 25 of the projection 9 and the breech block 5 carries out the recoil in conjunction with the carrier 3 with simultaneous compression of the propelling spring I5. During the recoil, the springs I1 remain compressed as illustrated in Figure 2.

After the recoil, during which the empty cartridge is ejected, has been carried out, the breech mechanism carries out the forward movement owing to the force of the compressed propelling spring I5. As soon as the mechanism comes into the position'illustrated in Figure 3, the pins I4, owing to the action of the curved lugs I3, lift the breech block 5 so that the edge 24 comes out of engagement with the surface of the vertical wall 25, with the result that the relatively rigid connection of the breech block 5 with the carrier is severed and the breech-block carrier 3 carries out an accelerated movement in relation to the breech block on account of the action of the compressed springs I1. When this is being done,

the edge 24 slides on an oblique face of the projection 9 and, owing to the accelerated forward movement, the lockingof the breech block 5 is completed by the action of the projection 9. The locked breech block is supported by the projection 9 of the carrier and, at the end of the forward movement, the end face of the projection 8 strikes the firing pin 2l, the firing of the cartridge is effected and the operation is repeated.

In the example illustrated in Figure 4, the breech block 5 is in the form of a cylindricaI body which is rotatably and displaceably mounted in the breech-block carrier 3 and is provided, on the side which faces the cartridge chamber, with locking lugs 26 which co-operate, in known manner, with grooves in the casing 2. On the end of the breech block there is applied a spring I1 which forms a resilient element,between the breech block 5 and the breech-block carrier. The

spring I1 bears at one end against the head 21 of the breech block 5 and at the other end against the part 3" of the end wall oi the carrier which forms the bearing for the rotatable breech block 5. The control of the breech block on the recoil and running forward movement is taken care of by an arm 28 which carries the firing pin 2l and is guided in a groove 29 formed in the breech block.

After firing, thebreech block carrier, after travelling through a short distance, which corresponde to the length of the longitudinal part of the groove 29, begins to rotate the breech block into the unlocked position under the action of the curved part of the groove 29. From the commencement of the recoil and also during this unlocking movement, the propelling spring I5 is tensioned on the one hand and the spring I1, in which energy is thus stored up, is tensioned on the other hand; this energy is released on the completion of the forward movement. Owing to. the turning of the breech block 5, the locking lugs 26 come out of engagement; in known manner and, after unlocking, the breech block carries out the recoil with the breech-block carrier behind which the propelling spring I5 is compressed. On the forward movement, the carrier 3 carries the breech block until the locking lugs drop into the grooves in the casing 2. From that moment, the spring I1 begins to act upon the breech-block carrier 3 and the spring I5, so that the carrier performs an accelerated movement in relation to the breech block, during which movement the locking of the breech block is accelerated considerably. As soon as the breech block is locked and the projection 28 has travelled, together with the tiring pin, through a distance which is equal to the length of the longitudinal part of the groove 29, the firing of the cartridge is eifected'and the operation is repeated.

The two embodiments above described are given only by way of example and may be varied in details without departing from the scope of the invention. Thus, for example, the number of the springs employed in the device, which render possible the movement of the carrier in relation to the breech block, or the kind of iirearm ernployed, such as, for example, firearms with a sliding barrel and the like, is immaterial.

What I claim is:

1. An automatic firearm comprising a barrel, a casing fixed to said barrel, a breech block reciprocating in said casing, a carrier for said breech block also reciprocating in said casing, recoil responsive means for reciprocating said breech block and said carrier, apertured abutments mounted on said carrier, rods having heads thereon positioned in the apertures of said abutments spring encircling said rods bearing one end aganstsaicl head and at the other end. against said abutments and said heads bearing against supporting surfaces on said breech block so that upon recoil of said carrier said springs are placed under compression which is released when said breech block is in ring positicn so as to cause a relative movement between Y said carrier and said breech block.

'block having a cylindrical body portion and a collar thereon, a carrier for said breech block, recoil responsive means located between said collar and said carrier and recoil responsive means llocated between said casing and said carrier.

vcLAv HoLEK. 

